| 摘要 |
PURPOSE:To transmit an arrangement telephone number (OW)- a monitor num ber (SV) signal and simultaneously monitor a bit error rate pf a main signal by converting into and transmitting a code mark inversion (CMI) code and applying aviolation. CONSTITUTION:When an OW-SV signal is applied at a transmission side, this signal is given to a pulse number modulation circuit 2, and herein, when the OW-SV is 1, a continuous violation pulse V for 3 bits of a NAZ is produced and when the OW-SV is 0, 2 bit continuing violation pulse V is produced. A conversion circuit 1 converts the NRZ code of a main signal into a CMI code. In this conversion, only when the violation pulse is 1, an output breaking a regulation of the CMI code is given. In a receiving side, an input is done to a demodulation circuit 3, and herein, a NRZ data is separated from a violation signal. The violation signal thereof is demodulated into the OW-SV signal by a pulse number demodulation circuit 4. Then, during this demodulation, when only 1 bit of the violation signal V appears, this is considered to be generated by a bit error such as noises during a transmission and inputted to an error rate detecting circuit 5 and a bit error rate of the main signal is outputted. |
